In recent years, liquid crystal display devices and organic electroluminescence (EL) display device are widely used as display devices of, for example, smart phones, personal assistant devices (PADs), tablet computer and car-navigation systems. These display devices mostly comprise a touch sensor which detects approach or a touch of a finger. Such a display device includes, for example, a first substrate provided with a plurality of electrodes and wiring lines and a second substrate disposed to oppose the first substrate. On the second substrate, a plurality of detection electrodes and wiring lines, which constitute a touch sensor, are provided. The wiring lines on the second substrate are electrically connected to the wiring lines of the first substrate, for example, via a flexible printed circuit board (FPC) or conductive paste such as silver paste and the like.